SINGAPORE, March 14 (Reuters) - A senior execution manager has left Louis Dreyfus Co (LDC) after nearly three decades at the commodities trading giant to join startup Sierentz Global Merchants.

Jean-Christian Fages, who worked at LDC for 28 years and most recently held the post of senior expert - international trade execution, told Reuters on Wednesday he plans to begin in a similar position in the new company.

“I will be director of execution, that is what is my expertise,” he said. “We have everything to do, it is a start up.”

Sierentz, a family holding of Louis-Dreyfus members, officially launched a new agricultural commodities trading firm earlier this month with a primary focus on exporting grain from the Black Sea region.

David Ohayon, who had been Head of Grains at LDC, left the agricultural major along with a group of other colleagues in August 2017 after differences of opinion with the company’s management.

“We are going to concentrate on Black Sea,” Fages said. “We will focus on whatever makes sense. Asia is one of the areas where there is lot of growth in grains demand.” (Reporting by Naveen Thukral in SINGAPORE, Sybille de La Hamaide and Gus Trompiz in PARIS; editing by Richard Pullin)